Open Stack

On Fri, 2014-04-04 at 13:30 +0800, Jay Lau wrote:
> 
> 
> 
> 2014-04-04 12:46 GMT+08:00 Jay Pipes <jaypipes at gmail.com>:
>         On Fri, 2014-04-04 at 11:08 +0800, Jay Lau wrote:
>         > Thanks Jay and Chris for the comments!
>         >
>         > @Jay Pipes, I think that we still need to enable "one nova
>         compute
>         > live migration" as one nova compute can manage multiple
>         clusters and
>         > VMs can be migrated between those clusters managed by one
>         nova
>         > compute.
>         
>         
>         Why, though? That is what I am asking... seems to me like this
>         is an
>         anti-feature. What benefit does the user get from moving an
>         instance
>         from one VCenter cluster to another VCenter cluster if the two
>         clusters
>         are on the same physical machine?
> @Jay Pipes, for VMWare, one physical machine (ESX server) can only
> belong to one VCenter cluster, so we may have following scenarios.
> 
> DC
>  |
> 
>  |---Cluster1
>  |      |
> 
>  |      |---host1
>  |
> 
>  |---Cluser2
>         |
> 
>         |---host2
> 
> 
> Then when using VCDriver, I can use one nova compute manage both
> Cluster1 and Cluster2, this caused me cannot migrate VM from host2 to
> host1 ;-(
> 
> 
> The bp was introduced by
> https://blueprints.launchpad.net/nova/+spec/multiple-clusters-managed-by-one-service

Well, it seems to me that the problem is the above blueprint and the
code it introduced. This is an anti-feature IMO, and probably the best
solution would be to remove the above code and go back to having a
single nova-compute managing a single vCenter cluster, not multiple
ones.

-jay